Nov. 7 (Bloomberg) -- Novartis AG is developing a version
of a hormone found in pregnant women in a bid to reduce deaths
from heart failure.

RLX030, an experimental drug that’s a man-made version of
the hormone, reduced death rates by 37 percent in patients with
a common condition called acute heart failure six months after
treatment, according to a clinical trial presented yesterday at
the American Heart Association meeting in Los Angeles. The
medicine is the only treatment to lower mortality, the company
said in a statement today.

Novartis stands to gain $1 billion in annual sales by 2018
if RLX030 makes it to market, according to Seamus Fernandez, an
analyst with Leerink Swann & Co. in Boston. First the Basel,
Switzerland-based company must convince regulators and doctors
that the result of the relatively small trial wasn’t a fluke,
said Milton Packer of the University of Texas Southwestern
Medical Center in Dallas.

“If that mortality benefit is real, boy are we going to be
excited,’” said Packer, who chairs the center’s department of
clinical sciences and wasn’t involved in the 1,161-person trial.
“The real question is whether the mortality difference seen in
this trial is a true and replicable finding.”

Novartis plans to submit the drug, also referred to as
Relaxin, to U.S. regulators next year. The company doesn’t think
it will need another clinical trial to receive marketing
approval, said Ameet Nathwani, who is in charge of Novartis’s
critical care products.

‘Robust’ Data

“Our perspective is that our data is robust,” Nathwani
said in an interview before the study was released.

Acute heart failure often occurs in the wake of other
trouble such as hypertension, diabetes or coronary artery
disease and may strike about one in 10 people over the age of
65. Doctors now use a mix of drugs and devices to help patients
feel better; still, half of those hospitalized don’t survive
longer than five years. RLX030 is a manufactured copy of
relaxin-2, a hormone whose levels rise during pregnancy.

Doctors say heart failure is like “drowning alive,” as
fluid rapidly collects in the lungs. Patients experience
shortness of breath and a swelling of their limbs, coughing,
weakness, fatigue and an irregular heartbeat.

In the acute version, there can be a sudden worsening of
the chronic condition, in which the heart muscle loses its
ability to pump blood.

Pocket Gophers

The hormone, first found in pocket gophers by an American
zoologist in the 1920s, is thought to relax blood vessels in
pregnant women. Researchers now believe that it helps heart
patients by protecting heart cells and kidney function, Nathwani
said.

Together with the experimental compound LCZ696, Relaxin may
help Novartis build a portfolio of heart-failure drugs. The
company needs to replenish its product line-up as the heart drug
Diovan and the cancer treatment Gleevec, its biggest sellers,
start to lose patent protection. They make up about 18 percent
of Novartis’s $58.6 billion in annual revenue.

Novartis acquired Relaxin in the 2010 purchase of closely
held Corthera Inc.

Cardiologists at the AHA meeting are getting the first
detailed look at the late-stage study known as RELAX-AHF.
Novartis released bare-bones results in September.

Besides reducing death rates, Relaxin helped ease shortness
of breath, which is one of the most common symptoms of acute
heart failure, according to the study. Helping patients breathe
easier was the main goal of the study, which looked at death
rates as a secondary measure.

Still, the drug didn’t keep patients out of the hospital in
the 60 days after the intervention. Also, RLX030 cut neither
cardiovascular deaths nor heart or kidney failure after 60 days,
which were secondary goals of the study.

Hospital Setting

This may make doctors cautious about whether the drug’s
effect on mortality will hold up in a hospital setting, said
John McMurray, professor of cardiology at the University of
Glasgow School of Medicine in Scotland. Another concern is the
small number of deaths, with 41 in the Relaxin arm, and 64 in
the placebo group, he said.

“Small numbers often don’t give you robust and reliable
estimates of benefit,” he said. “If we did replicate this
finding, it would be an extraordinary advance in the management
of acute heart failure, for which we have no disease-modifying
or life-saving therapies.”

The drug didn’t show any serious safety issues in the
study. “It’s very comforting that women have high levels of
Relaxin during nine months,” Nathwani said. “It looks
incredibly well tolerated.”

Earlier Drug

An additional caveat may be the shadow of Natrecor, a
Johnson & Johnson drug introduced in 2001, according to Tim
Anderson, an analyst with Sanford C. Bernstein & Co. in New
York.

Natrecor, given intravenously, was one of the first drugs
for congestive heart failure when it was approved, and in 2004
it generated $230 million in revenue. Sales were more than
halved in 2006 after reviews of its use in less than 1,000
patients tied the medicine to worsening kidney function and
higher death rates. A later study of 7,141 patients found the
drug to be safe, though it only slightly improved symptoms.

“Unfortunately, this sets the bar high for Relaxin,”
Anderson said in a note yesterday.